is a map editor for Id Software's popular Quake game. THRED provides an easy-to-use 3-D environment for creating Quake maps. It has a number of advanced features, including 2D and 3D preview modes; walkthrough and live positioning in the preview modes; flexible brushes for creating surfaces; dialogs that allow you to create stairs, rings, and other map elements which you can then rotate, scale and place in your map; automatic scaling of complex objects down to elements that Quake can handle; and more.